The present invention pertains to a system for display of computer data. More specifically, a system is provided for simultaneously displaying different groups of computer data on a display screen at different resolutions.
Computer data is displayed on display screens of computer monitors. A computer monitor screen contains dots which are illuminated in patterns to form images (letters, numbers, pictures, and other graphics). The dot is the smallest physical unit which makes up a computer graphics image and on certain video display screens consists of a dot of phosphorous on the screen. These phosphorous dots give off light when bombarded with electrons from a cathode ray tube.
A pixel is a picture element and, from the perspective of computer software that outputs display data, it is the smallest element of a graphics image. The display data and commands output by a software program are processed by a display driver and output as graphics data to a graphics controller, which controls the display of each pixel on the screen. Each pixel may comprise several dots, or even a single dot, as in very robust display systems. The number of pixels capable of being displayed by the fixed number of dots on a screen is the resolution of the screen. The screen resolution, therefore, represents both the number of pixels capable of being displayed on the screen, and the number of dots in each pixel. The lower the resolution, the more dots per pixel, and the larger each pixel appears. The higher the resolution, therefore, the lower the number of dots per pixel, and the smaller each individual pixel appears. Program outputs or image files formatted for higher resolutions contain more pixels and therefore, more memory is required to store the images.
While the number of dots on an entire display screen is fixed, the number of pixels on the screen can often be adjusted, thereby adjusting the resolution. This is a feature of, for example, the Microsoft Windows(copyright) 95 operating system in which the user can adjust the number of pixels to be displayed on the screen (e.g. 640 pixelsxc3x97480 pixels, 800 pixelsxc3x97600 pixels, 1024xc3x97768 pixels). By changing the number of pixels displayed, the user is also changing the number of dots per pixel. The more pixels displayed on the screen, the fewer dots per pixel, and the higher the resolution of the images on the screen. Higher resolution images appear xe2x80x9csharperxe2x80x9d to the user because the eye is less able to distinguish the fact that the image is made up of individual pixels due to the smaller pixel size. xe2x80x9cSharpness,xe2x80x9d therefore, is a description of how an image on the screen appears to a viewer.
By decreasing the number of pixels capable of being displayed on the screen (decreasing resolution), the number of dots per pixel is increased, and the sharpness of the images on the screen is decreased. By increasing the number of dots per pixel, decreasing the resolution not only decreases the sharpness of the images, but it also increases the size of the images on the screen. Conversely, decreasing the dots per pixel (increasing the resolution) increases sharpness and decreases the size of the image. There exists, therefore, an image size, sharpness tradeoff. High resolution corresponds to small image size, with more information able to be displayed on the screen. Low resolution corresponds to large image size, with less information capable of being displayed on the screen.
Presently, computer display systems are capable of displaying multiple text and graphics images corresponding to different software programs simultaneously on the screen. Common examples of this are the Microsoft Windows(copyright) 95 operating system, and the Macintosh(copyright) operating system (Version 8.0, Apple Computer, Inc., Cupertino, Calif.). These systems can simultaneously display the output of multiple programs in multiple xe2x80x9cviewing areasxe2x80x9d on the screen. In these current systems, each software program running on the computer generates an output of display data and commands which represent values for a specific number of pixels. The operating system takes this program display data and organizes it for display (via the video controller) along with display data from other programs and the background display data of the operating system. Based on the size and position of the display viewing area for each program, the operating system determines which portion of the program""s display output will be shown on the view screen. By re-sizing a display viewing area, a user can choose to display a smaller or larger portion of the total pixels output by the software program.
A user may adjust the total screen resolution (i.e. change the total number of pixels displayed). This changes the number of dots per pixel (and therefore the image sizes, the sharpness, and the total amount of information the user can see on the screen). There is presently no capability, however, for displaying different viewing areas at different resolutions. A user cannot presently choose to have two viewing areas simultaneously displayed with different values for the number of dots per pixel. Because of the sharpness/image size tradeoff, this would be a desirable feature, as a user could then display, for example, a picture file at a low number of dots per pixel, with high resolution and small image size, while simultaneously displaying a word processing program with a significant amount of text at a high number of dots per pixel, low resolution, and large image size. This would allow for a large portion of the picture to be shown on a small viewing area, with optimized appearance due to the high sharpness, while the text of the word processing program is displayed large enough to allow for easy reading and editing.
Some programs that are run on current systems were developed when display screens were capable of displaying fewer pixels than is possible today. Both dots and pixels were larger on the old display systems. Programs designed for those systems, therefore, are displayed on current high-resolution systems as smaller viewing areas. The programs output the same number of pixels as they do when run on older systems, but the number of dots per pixel has decreased (as has the size of the dots) so the same number of pixels takes up less area on the computer display screen. Current systems are not capable of increasing the size of these viewing areas without changing the dots per pixel of the entire screen. It is desirable to create a system which would appear to the user as an increase in the dots per image (or application) for such programs, while allowing other programs to be displayed at the dots per pixel value which has been selected for the rest of the screen. It is desirable, therefore, to allow the user to adjust the apparent number of dots per pixel independently for independent viewing areas. This will make it possible for it to appear to a viewer that two viewing areas of the same size are displaying different numbers of pixels.
According to an embodiment of the present invention, a video display system is provided including a first viewing area on the video display system having a first resolution, and a second viewing area on the video display system having a second resolution, where the first resolution is higher than the second resolution.